To understand the benefits of Unified Command, first we need to know what exactly is a UNIFIED COMMAND.
Answering above : All agencies with geographical or functional responsibility for an incident may designate an Incident Commander to a Unified Command organisation through the collaborative process of unified command. Then, the Unified Command develops a set of incident objectives and methods that everyone can adhere to.
Now, coming to the options, we can clearly see that all the given options are the benefits of Unified Command.
So, all the given options are correct.